Air-brake



Y 2 Sheets-Sheet 1. N. J. PRITGHARD 8a J. S. TEMPLON.

A1B. BRAKE.

Patented Mar. 5, 1889.

(No Model.)

i W a S\w\\\\\\\\\\\\\\\\\\\\\ mg C N. PErEns. Phuwumuyapher. wnnngmn. D c.

(No Model.) 2 Sheets-Sheet 2.

N. J. PRITCHA'RD 8v; J. S. TEMPLON.

.AIR BRAKE.

No. 399,158. Patented Mar. 5, 1889.

i Maase n l pfm/Vfa i) @Zeocg W 32W@ moww JQ/50V mmm. wmmgim n, c,

UNITED STaTns PnTnNT @Tricel NATHANlEL l. PRl'lC-llARD AND JAMES S. TETHILON, OF MILNES, ASSIGNORS, BY DIRECT AND )IESNE ASSIGNMENTS, TO THE PRlTCllARll BRAKE COMPANY, OF ROANOKE, VIRGINIA.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 399,158, dated March 5, 1889.

Applieation'led April 13, 1888. Serial No. 270,568. (No model.)

To all 'lt-7mm it may concer/z:

Be ity known that we, NATHANEL J. PRTCH- i ARD and JAMES S. TEMPLON, citizens ot the i being preferably adapted to be arranged in 5o United States, residing at lililnes, in they county ot Page and State of Virginia, have invented certain new and useful Improvements in Air-Brakes; and we do hereby declare the following to be a full, clear, and e:\'-

act description of the invention, such as will short tubular box, o, to receive the upper end enable others skilled in the art to which it appertains to inake and use the saine.

l l l l l l Our present invention` relates to a device i closed by means of; a plate securely fastened for use in applying pressure to pneumatic railway-brakes, its particular and preferred purpose and use heingthatot eontrollingand y i toni any drippings or other wa, ye that may regulating the admission ot air to the brakecylinder; and it consists, essentially, in the construction, arrangement, and combination oi' parts, substantially as will be hereinafter described and claimed.

In the accompanying drawings, illustrating our invention, Figure l is a vertical section ot' ouriinproved device for applying pressure to pneumatic railway-brakes, and shows the piston at the upper limit of its stroke. Fig. i is a horizontal section on the line mx of l? ig. l. rFig. il is a similar vertical section to that shown in Fig. l, with the piston occupying its lowerinost position, or the position taken when the greatest amount of air is being introduced into the brake-cylinder. Fig. l is an enlarged perspective view ol the senti-cylindrical paehingwing. ltig. 5 is a sectional detail showing the relative position of the piston-rod and its disks, the packing-ring with its ports, and the port leading to the brakeeylinder when a certain fixed amount of pressure is upon the brakes, and is held there with the port closed against the entrance of more air. Fig. G is a similar sectional detail showing the arrangement oi' the same parts when air is permitted to pass through the ports and passages ot the packing-ring and onward into the binne-cylinder.

Similar letters ot reference designate correspending parts throughout'- the different tigures.

A denotes a eyliuder, oi? any suitable dimensions and niade in any desired manner, it

an upright position beneath the ear or other vehicle with which it is used. It may beniade in one or more parts, as preferred. lu the drawings a convenient construction is shown, consisting ot the main cylindrical body, upon the top et which is a cap-plate, Af, securely bolted thereto and formed centrally with a.'

of the piston-rod, and thus guide the saine during the movements oi' the pistou. The lower end oi' the niain cylindrical body is over it, and carrying a bulb-shaped air-chainber, B, which is adapted to rec ive at its botaccumulate therein, whence they are reinovable through a drain-cock, (l.

The cylinder A is provided with ports at points where the several pipes are coupled, that are used with the ordinary airbral e and lead to the essential parts oi' the saine.

Thus C denotes the port where a coupling is made. with the pipe that leads to the airdrurn or auxiliary cylinder.

D is the port where the pipe is connetifted leading to the brake-cylinder.

E is a port situated in the wall o'l the bulb B at a point where it entered by pipe F, that leads to the main airsupply` pipe.` and through said pipe l? air is i ntrodueed into the device. At port l) is connected a T-shaped pipe, having a horizontal portion extending outward lroin the cylinder A, at right angles to which portion is another horiaontal part, l-l, a plug-valve, H', being located atthejunction ot' these two horizontal parts. 'lhis valve will be ordinarily turned in the posit-ion shown in lfig. 2, where air may pass in one direction or the other between the port l) and the pipe l, leading to the brake-eylint'ler and coupled to one end of the pipe li.

A short distance below the port D in the wall ot.' the main body rr is located an exhaust'- port, Through this exhaust-port the air 'from the bral e-cylinder will have t'ree egress when the brakes are relieved. A vertical passage, o, extends upward thrtnigh the wall ot the cylinder A to the port (l, said passage c having' a coii'ln'iunication near the bottom oi the cylinder by port d with the interior oi' the lcylinder' A. 'lhrough the port (Z air coming under pressure Yl'rom the main supply-pipe will pass into the passage r' on its way to the ai r-d rum.

iithin the central chamber ot' the device is located a suitably-constructed piston, J, adapted to move vertically. 'lo the piston J is connected avertical piston-rod, G, whose upper end is received into the tubular box o, above mentioned. The piston J is located near the bottom of the cylinder A and reciprocates within narrow limits in that portion ot' the cylinder, the upper limit of its movement being shown in Fig. l, and itslowermost position being seen in Fig. 3. The piston-rod G is provided with two `fiat circular plates or disks secured horizontally thereto at a suitable distance apart and at proper points in the length of the rod, the upper ot theseplates being denoted by L and the lower b vK. Between these two horizontal plates K vand L is located e semi-cylindrical or semi-annular valve, M. lt is shown in perspective in Fig. 4. It has a semicircular groove along one side, which receives the piston-rod. It has a radius ot' sufficient length to enable it to be situated eloselybetwecn the wall of the main body A and the piston-rod, although the ttingis loose enough to enable the said ring M to have `t'ree movement up and down. A semiriug is used instead ot' a complete ring, in order to make the Adevice cheaper and lighter, and for the purposes of its construction it will serve equally well with a completely annular ring. This valve M may vary in size, structure, and shape without departing from the spirit of our invention. shorter than the vertical length of the annular space between the plates K and L, within which it is contained, as will be evidentupon. inspection of the figures 'of the drawings; hence it will be perceived that the piston with its piston-rod, and consequently the plates or disks l( and li, may have acertain amount et' vertical movement without displacing the valve M from its position. Said valve M is furthermore provided with a vertical groove, g, in its outer surface, into which groove proj eets a screw or pi n, 71, fixed in the wall ot the cylinder A. 'ly means ot'fthis pin entering the groove g/ the valve )l may move vertically without being susceptible oii any retary displacement; also, the valve Ais recessed on its outer face at m, as also at m. The recess on. is cutout ior a portion of the circumferential distance ot the valve, and is ot sutticient size so that when the valve is adjacent to the ports l) and c, as shown in Fig. l, they may be con'nectefil, thus allowing the air to be exhausted .from the lnakc-cyliinler.

The under or bottom surface of the valve is provided with a port at b', and the outer surface of the valve is furnished with another port at b2 in the recess on. The ports b and b2 are connected by a passage, L, ruiming Its vertical length is through the material of the valve. The direction of this passage is ot course unimportant; but for convenience in construction' it preferably partakes of that direction shown in the drawings, where it runs vertically and then horizontally.

The port b is adapted to be closed by the disk or plate K. Said port has a packing ot suitable material-such as leather, gum, rubber, or other suitable sub` stance-so that a tight joint may be effected.'

position shown in Fig. l, where it is at its up-v permost limit. The semi-ringnow rests upon the lower plate, K, the port h being closed. It may be noted in this connection that as the piston moves upward the disk K, by pressing on the packing-ring, pushes it up. As the piston moves downward, the disk L, being in contact with the ring M, assists it to descend. ln Fig. l. air is entering the device through the pipe F, passing upward beneath t-he piston J, thence out through port (l, and along passage c into port C and into the air-drum. The pressure oi.' the incoming-air is sufficient to uphold the piston and its connections.

Suppose now that it is desired to set the brakes. The engineer' will determine the amount of pressure which he desires to apply to the brakes and adjust his regulating-valve accordingly. \\'hether a greater or less pressure is needed will of course depend upon the circumstances of the case. The proper manipulation ot' the engineer-s valve will exhaust air from beneath the piston J, so that saidpressurebeneath the pist-on will be less than the pressure above it. Consequently the piston will begin to descend, thus causing' the disk l, to come in contact with the valve M and the disk K to be removed from the position where it closes the port b. As the piston continues its descent, the valve will be pushed downward until at length the port b2 in said valve M will come into coincidence with the port D in the manner shown in Fig. (i. Air will now begin to pass through the port b and upward through the valve, then out tln'ough port ZF into port D and onward to the ln'ake-cylinder, where it will act to set the brakes. The continued outiiow of air to the brake ylinder will in a short time cause the air-pressure in the air-d rum and above the main piston J to be less than the airpressure beneath the piston, it being remembered that the port d is now closed, so that air in the air-drum is not subject to increase at this time. The result of this inequality ot pressures on the upper and lowel" faces of the piston will be to cause the latter to adjust itself slightly; hence it will ascend a little, j ust suiiieient to close the port b and prevent the outiiow'of any more air, although the movement of the piston will not be suiiicient to displace the valve from posit-ion. The relation of the parts at this time is clearly shown in Fig. 5, where the disk K is covering the port b and excluding any more air from entering it. The brakes are now set with a certain pressure of air, and this pressure of air will be maintained steady and constant until the engineer wishes to change the condition ot things and again manipulates his valve. By the use, therefore, of this valve, constructed as described and so related to the other parts of the invention as we have indicated it, the amount of air which is admitted to the brake-cylinder may be graduated, regulated, and governed completely, so that the engineer is enabled to set the brakes at a certain desired pressure and keep them at this pressure until he wishes vto release them.

lVlien the engineer desires vto relieve the brakes, enough air will be admitted below the piston .l to drive it upward, causing it to rcsume the posit-ion shown in Fig. l, where the recess on in the valve connects the port D and the exhaust e. Egress of air in the brakecyliuder cannow easily take place by passing in the direction of the arrow shown in Fig. l through ports D and exhaust e.

When the engineer wishes to apply lo the .brakes the full amount of pressure ot which his apparatus is capable, he will exhaust enough air from below the piston .l to compel it to assume its lowermost position, as shown in Fig. Si. ln this position the air will not pass through the valve, but will rush directly, as shown by the arrows, lfrom the interior ot' the cylindrical body A, through port D, tothe lnake-cyliinler.

Having thus described our invention, what we claim as new, and desire to secure by lietters Patent, is-

l. In a device for applying' and relieving the pressure on pneumatic railway-brakes, lle combination of the inclosin g -case having ports leading to the air-drum, main pipe, and

brake-cylinder, an exhaust-port, and a vertical passage extending` upward through the wall of the cylinder to thev port that leads to the air-drum, said passage having communication near the bottom of the cylinder by a port with the interior of the cylinder, the capvplate-for the cylinder provided with a downwardly-extending tubular box, the piston and its piston-rod, the upper end of which is received into said tubular box, the two iiat circular plates or disks secured upon said piston-rod, the valve located between said plates,

'and consisting of a semi-cylindrical piece of pneumatic pressure on railway-brakes, the

combination of the main cylindrical case A, having the port C, leading to the air-drum, port D, leading to the brake-cylinder, port E, leading to the main air-supply pipe, a-n exhaust-port, e, and a vertical passage, c, extending upward through the wall ot the cylinder to the port (l, said passage c communieating by port d with the interior of cylinder A, the cap-plate A Vfor the main body A, pro vided with a downwardly-projecting tubular box, o, the piston .l and its piston-rod G, whose upper end enters the tubular box o, the two iat circular plates K and L, secured upon the piston-rod, the valve M, located between said plates or disks, and having a bottom port, b', a lateral port, lr", and a connecting-passage, li, between sai d ports, the port Zi being adapted to be closed or opened by the disk or plate l, all the parts being arranged l'or joint operation, substantially described, and for the purpose specilied.

In testimony whereol we a t'ti v ou r signatures in presence of two witnesses.

NATHANIEL J. PRITCHARD. JAS. S. 'l'EMPliON XV itnesses:

Wn. H iis, '.Liiins Maenner. 

